Can cultural practices such as irrigation, pollination, fertilization, pruning, cultivation under plastic tunnel or net influence the pest and disease spread and development?
This task will mainly focus on Psa and Ds. Concerning Psa, but also Xap, the major activities in kiwi fruit and stone fruits cultural management are represented by pollination, irrigation, fertilization, use of bioregulators and pruning. The role of each of these activities on disease incidence and development will be firstly evaluated in small-scale experiment and, on the bases of the results obtained, field experiments will be designed. The relative importance of the different cultural practices will also be investigated in real orchard conditions. For the different cultural activities, together with the data about disease incidence and development, also the microclimatic conditions inside plant canopy and the major biometric performances will be recorded (e.g. photosynthetic rate, shoot elongation, fruit production and quality, specific leaf area, stomatal conductance, leaf chlorophyll content).
Role of pollination. Pollination is crucial to obtain good harvest and good kiwi fruit quality. The experiments will aim to: 1) evaluate the susceptibility of commercial males and the possible consequent production of infected, 2) evaluate the role of pollen as a possible vector for Psa according also to the techniques used to harvest the pollen and 3) the influence of pollen spread methods on disease diffusion.
Role of irrigation. In European conditions irrigation of kiwifruit trees in a common practice. The experiments will be performed on potted plants subjected to different water inputs. On those plants the major biometric parameters (e.g. shoot elongation, specific leaf area, photosynthetic rates, water potential, stomatal conductance) will be constantly monitored to take in account the possible water stress. On the same plants also disease development and incidence will be recorded after experimental inoculation. The data obtained in controlled conditions will be correlated with the data obtained by questionnaire and by survey of commercial farm applying different irrigation strategies.
Role of fertilization. The role of both macro- and micro-elements will be investigated. Different forms, amounts and combinations of P, N and K fertilization will be evaluated on potted plants in controlled conditions. The role micronutrients disease incidence and development will be initially evaluated by subtracting separately each them from a standardized artificial growing medium. The results obtained by the deficiency of each of the single microelements will be used to design medium-scale experiments.
Also alternative fertilization strategies, such as foliar nutrition, will be evaluated.
Role of pruning. Pruning activity lead to open wounds that might represent and important entry point for the pathogen. The experiments will aim to: 1) identify for how long a pruning cut is a risky entry point, 2) compare different sealing methods to reduce pathogen penetration, 3) identify most reliable, and time-efficient methods for sterilizing pruning tools, 4) develop methods to minimize pruning activity (e.g. use of growth retardants, root slashing) and 5) compare the different pruning strategy (e.g. summer or winter pruning). The final aim is to identify the best pruning protocol to minimize the risk of infection and that at the same time ensures the best plant performances.
Use of plastic tunnel and netting. The effect of kiwifruit cultivation under plastic tunnel will be evaluate both on plant productive performances and disease development.
Concerning Ds, cultural practices (e.g. clean harvest, wild fruit removal, netting) that limit abundance of, and damage by D. suzukii will be developed and tested. Experiments will be carried out in berry fields in China and in various berries, grapes and stone fruits in Spain, and Italy. The information gathered in this task will be used to improve the Decision Support System and will be used in dissemination activities to stakeholders in commercial field testing.
How can growers and advisers decide how to implement integrate pest management measures, particularly for new pests and diseases?
It is especially difficult to decide what steps should be taken to control newly introduced pests when there is still very little direct farm-level knowledge in the region. The Dropsa project is gathering information on control of new pests such as Spotted-wing Drosphila and Kiwifruit blight from many sources, including new field and lab testing by project partners. This information will be brought together to create a decision support system (DSS) of tables, diagrams and figures available on-line to show the performance of individual and combined measures, based on the efficacy, feasibility and economic analysis of different combinations of selected pest management practices. Direct experience of control measures will be collected through an online user interface (made available on the project website and on the EPPO website) which will allow model decision inputs to be updated and validated.
Which IPM strategies are developed?
All the knowledge gathered in the project will be integrated to develop different IPM strategies based on most reliable and effective combinations of products and cultural techniques.
IPM strategies will be developed for different cropping systems and different regions. The IPM strategies will include both D. suzukii and/or disease aspects of crop management.
In order to increase sustainability and to minimise the negative anthropic impact, the phytosanitary treatments and the cultural interventions (e.g. pruning) will be tailored on the risk map and the DSS.
Modern fruit production must ensure consumer satisfaction and deliver high value quality fresh fruit that contributes to a healthy diet and overall wellbeing (see EU project ISAFRUIT). In this holistic view, fruit quality should consider not only the organoleptic and nutraceutical value, but should also absence of contaminants such as pesticide residues, achieved through ensuring agricultural practices that reduce pesticide impacts on the environment and promote biodiversity. This goal will be achieved through the IMP strategies developed in DROPSA which will harmonize the most efficient cultural practices with the most effective disease control methods.
Department of Agricultural Sciences
Faculty of Agriculture and Veterinary Medicine
Alma Mater Studiorum -University of Bologna (Italy)